Gas-Pro IR



The infrared measurement gives improved reliability and measures gas in two different wavelengths: one that absorbs gas and the other does not. With little chance of being poisoned, the Gas-Pro IR personal multi gas detector is inherently safer and saves the need of regular and expensive pellistor replacement when used in likely contaminated environments.

The Gas-Pro personal multi gas detectors are known for their simple use and functionality as well as easy testing and calibration. The Gas-Pro IR now completes the Gas-Pro range and gives greater flexibility for sensor selection in this 5-gas multigas detector.

IR Technology

Infrared emitters within the sensor each generate beams of IR light . Each beam is of equal intensity and is deflected by a mirror within the sensor on to a photo-receiver, which measures the level of IR received. The “measuring” beam, with a frequency of around 3.3μm, is absorbed by hydrocarbon gas molecules, so the beam intensity is reduced . The “reference” beam (around 3.0μm) is not absorbed, so arrives at the receiver at full strength.

The %LEL of gas present is determined by the difference in intensity between the beams measured by the photo-receiver.

IR sensors are reliable in some environments that can cause pellistor-based sensors to function incorrectly or in some cases fail:

  • In some industrial environments, pellistors are at risk of being poisoned or inhibited. This leaves worker on their shift unprotected. IR sensors are not susceptible so significantly enhance safety in these conditions.
  • Exposure to high levels of flammable gas can cause “sooting” of pellistors, reducing their sensitivity and potentially leading to failure Pellistors require oxygen to function. However, IR sensors can be relied on in applications such as fuel storage tanks where there is little or no oxygen, due to flushing with inert gas prior to maintenance or which still contain high levels of fuel vapours.
  • The fail-safe nature of IR sensors, which automatically alert you to any fault, provides an additional layer of safety.

Gas-Pro IR measures in %LEL and has been certified for use in hazardous areas as defined by both ATEX/IECEx and UL.

User Friendly

  • Top mount display – makes it easy to read at a glance
  • Simple single button operation – can be used whilst wearing gloves
  • Intuitive functionality – reduces training time


  • Monitor 5 gases in many different combinations
  • Pumped and diffusion solutions – offers multiple uses within one compact detector
  • Multiple languages
  • Automatic fail-safe flow plate recognition – takes away the pain of pre-entry testing
  • Specific and unique Pre-Entry Check (PEC) mode


  • Reliable lithium-ion battery – provides over 14 hr use from a 7.5 hr charge
  • Water and dust resistant to IP65 and IP67 – capable of withstanding harsh environments
  • Bump and calibration reminders – Full compliance


Size 43 x 130 x 84mm (1.7 x 5.1 x 3.3ins)
Weight 309g 4 gas (10.8oz)/ 340g pumped (11.9oz)
333g 5 gas (11.7oz)/ 362g pumped (12.7oz)
Alarms Audible >95dB @ 30cm (98dB @30cm in loud mode)
Visual – all angle dual red/blue LEDs
Vibrating alert
Display Top mount for ease of view with dual colour backlight (green/red)
Data logging 125 hr at 10-second intervals (45,000 logs)
Event logging Alarm, over range, calibration, bump, on/off, TWA, 1000 events
Battery Rechargeable Li-ion, >14 hr (13 hr pumped operation) based on CH4, O2, H2S, CO
Typical charge time 7.5 hr
Sampling Internal pump as option
Operating temperature -20°C to +55°C (-4°F to +131°F)
Storage -20°C to +65°C (-4°F to +149°F)
Humidity 10 to 95% RH
Ingress protection Independently tested to IP65
Approvals IECEx: Ex db ia IIC T4 Gb Tamb -20°C to +55°C
ATEX and UKCA: II 2 G Ex db ia IIC T4 Gb Tamb -20°C to +55°C
UL: Class 1, Division 1, Groups A, B, C, and D UL 913, UL 60079-0 and UL 60079-11
INMETRO: Ex db ia IIC T4 Gb Tamb -20°C to +55°C
Marine Equipment Directive: MED 1500009
Compliance FCC and CE
Complies with EMC Directive 2014/30/EU
EN50270 and ICES-003
Interface Data connection for gas test solutions and direct to PC
Charging Direct connection to multiregional power supply
Vehicle charger adaptor
Desktop cradle
USB power and communications lead
Crowcon Connect Compatible? Yes


Gases and Ranges

Gas Range Typical Alarms Resolution
PID  0-1000ppm  50ppm  1ppm
Ammonia (NH3)  0-100ppm  25ppm  1ppm
Ammonia (NH3)  0-1000ppm  N/A  1ppm
Carbon dioxide (CO2)  0-5% vol.  0-5% vol.  0.01% vol.
Carbon monoxide (CO)  0-2000ppm  20ppm  1ppm
Carbon monoxide (CO)  0-500ppm  20ppm  1ppm
Carbon monoxide
(hydrogen filtered)
 0-2000ppm  20ppm  1ppm
Chlorine (Cl2)  0 – 5ppm  0.5ppm  0.1ppm
Dual toxic (CO-H2S) H2S 0-100ppm
CO 0-500ppm
Flammable  0-100% LEL  20% LEL  1% LEL
Hydrogen (H2)  0-1000ppm  N/A  1ppm
Hydrogen sulphide (H2S)  0-100ppm  5ppm  1ppm
Nitrogen dioxide (NO2)  0-20ppm  1ppm  0.5ppm
Oxygen (O2)  0-25% vol.  19.5% / 23.5% vol.  0.1% vol.
Ozone (O3)  0-1ppm  0.1ppm  0.01ppm
Sulpher dioxide (SO2)  0-20ppm  1ppm  0.1ppm
Chlorine dioxide (ClO2)  0-1ppm  0.1ppm  0.1ppm
Nitric oxide (NO)  0-100ppm  25ppm  1ppm


Below is a small selection of the accessories available for the Gas-Pro IR.

Gas-Pro CSE Kit Case


Hard shell case including foam insert with space for Q-Test, 34 or 58ltr cylinder, power and comms cable, drop line, Gas-Pro, flow plate, filters, chest harness and straps and instructions – contents not included.

Gas-Pro Hard shell case


Includes custom foam insert with space for standard items – contents not included.

Sampling tube


Compatible sampling tube for Gas-Pro. Select length from list and whether standard or low adsorption material for reactive gases. All include tube insert to enable attachment to flow plate.

Hand aspirator bulb


For manual gas sampling. Use with appropriate flow plate and sampling tube.

Chest harness plate


Enables detector to be worn on the chest or over the shoulder. Use with straps AC0507 or AC0508.


Gas-Pro un-pumped flow plate

Gas-Pro un-pumped flow plate


Replacement flow plate for un-pumped Gas-Pro units.

Gas-Pro Pumped flow plate


Replacement flow plate for pumped Gas-Pro units.

Gas-Pro charger cradle


Desk or wall mounted cradle for charging Gas-Pro.





Power and Communication Cables


Basic Operation:


Includes: Switching Gas-Pro on and sensor zero. Duration: 1m:11secs

Watch video


Includes: Explanation of Gas-Pro alarm display. Duration: 49secs

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  Home screen

Includes: Gas level display home screen. Duration: 32secs

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Includes: Switching Gas-Pro off. Duration: 21secs

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Includes: Using the Gas-Pro cradle charger and charging lead. Duration: 33secs

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Includes: Activating the display backlight. Duration: 19secs

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Advanced Features:

  Flow plate

Includes: Fit and remove the gas flow plate on Gas-Pro’s with internal pumps. Duration: 44secs

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  Pre-Entry Check

Includes: Conduct pre-entry gas checks for confined spaces using Gas-Pro. Duration: 1m:18secs

Watch video

  Quick view

Includes: View status information without switching Gas-Pro on. Duration: 29secs

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Includes: View average toxic gas exposure measurements. Duration: 32secs

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  Peak review

Includes: Switch display to peak level readings. Duration: 46secs

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  Manual zeroing

Includes: Perform a sensor zero when in clean air. Duration: 32secs

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  Select user

Includes: Active user tracking. Duration: 49secs

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Bump Testing:

  Manual bump

Includes: Bump testing using the gas flow plate. Duration: 54secs

Watch video

Additional Information:

Gas-Pro user manuals and datasheets can be found in our downloads section.